Fewer people of working age means, obviously enough, fewer workers. It also means fewer potential entrepreneurs creating new businesses that hire people.

And aging isn’t the only demographic weight holding back the economy. For most of the 20th century, the share of women in the labor force was rising. It reached 60 percent in 1997, up from just 32 percent in 1948.

If you need confirmation of the impact of demography on the economy, just look at Japan.